An early and rare second malignancy in a treated glioblastoma multiforme: is it radiation or temozolomide?

Rare case of radiation-induced trigeminal schwannoma occurring in a long-term glioblastoma multiforme survivor

Glioblastoma multiforme (GBM) is a high-grade primary brain tumour with a notably poor prognosis. Research demonstrates a median survival of just over 1 year following aggressive treatment. Long-term survival is notably rare. Cranial radiotherapy and postexcisional prophylactic treatment is associated with the development of second, histologically distinct tumours in rare cases. Radiation-induced intracranial schwannomas are uncommon, with only a small number of cranial nerve schwannoma cases reported in recent decades. To our knowledge, this is the first reported case of a radiation-induced benign trigeminal schwannoma occurring following long-term survival from glioblastoma. Here we present (1) a rare case of 14-year survival following treatment of a right parietal glioblastoma and the development of a radiation-induced benign trigeminal schwannoma in a 35-year-old man, and (2) a review of radiation-induced schwannoma cases reported in the existing literature.